a. Field of the Invention
The present invention is relates to a random input multistage storage system for storing voltages from intermittent or unstable power sources as well as from a power grid, and more particularly, to a circuit system that utilizes a voltage difference between two or more than two stages comprised of two or more than two types of storage device, to store DC-converted city power, or charging energy randomly inputted from unstable sources such as a solar cell or a windmill generator.
b. Description of the Prior Art
The prior art involves the input of DC power which has been converted from AC using a contact type conduction structure for random coupling, or using electric energy outputted from a solar cell or a windmill generator or other unstable sources, such as tide generation or vibration generation to drive a load capable of random operation. However, during operation, the power supply is frequently disconnected due to intermittent operation of the contact type conduction interface, or the effect of ambient factors in case of solar or wind energy, or instability in tide or vibration energy. To cope with these defects, batteries are added to ensure a consistent supply of power according to the following options:
(1) A primary battery with positive polarity is added in series with an isolation diode before being connected in parallel with the output side of a random input source (such as in the application of a calculator with a solar cell);
(2) A secondary (dis)chargeable battery is connected in parallel with the output side of a random input source;
(3) A super capacitance is connected in parallel with the output side of a random input source; or
(4) A voltage stabilization capacitance is connected in parallel with the output side of a random input source;
However these options are further found to have the following defects:
Option (1) is not very convenient since in the connection of the primary battery in parallel with the output side of the random input source, any insufficiency of electric energy in the primary battery requires immediate replacement.
For options (2) and (3), a longer standby time for recharging is required to receive DC voltage converted from the city power, or the output of a solar cell or windmill through the contact type of conduction structure to allow for the rise up to normal working voltage, if the secondary (dis) chargeable battery or the super capacitance functioning as the battery is at low capacity. If a solar cell with higher capacity is used to simultaneously supply charging electric energy and loading electric energy, the installation of such a solar cell is comparatively expensive, requires a larger area and and therefore is generally impractical and not economic. Furthermore, it is far more difficult to control the immediate charging by relying on windmill generation.
Option (4) requires connection of a stabilizing capacitance in parallel and, if the capacity gets too small, fails to provide a high density output or if the capacity becomes too high, similar defects to those found with option (3) appear.
The primary purpose of the present invention is to provide a random input multistage storage system for unstable or intermittent voltages. To achieve this purpose, a circuit system controls storage based on a voltage difference between two or more than two stages comprised of two or more than two types of storage device, for storing DC-converted city power, or charging energy randomly inputted from an unstable source such as a solar cell or a windmill generator to correct those defects observed with the prior art.